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. R17N � <br /> ATTACHMENT 3 <br /> FIELDINVESTIGATION AND QAJQC PROCEDURES <br /> FOR GROUNDWATER SAMPLING <br /> Groundwater Sampling Procedures <br /> The <br /> depth to groundwater and total well depth were measured before sampling using an!;': <br /> electric water well sounder. Before sampling,x at least 3 casing volumes were purged from',; <br /> each well using a Teflon bailer. Throughout purging, pH, specific conductivity, and';: <br /> temperature were measured and recorded; for the evacuated groundwater. These <br /> measurements were used to confirm that the well was purged sufficiently. Water samples; <br /> were generally collected after the measurements of pH, specific conductivity, and: <br /> temperature had stabilized to within 10 percent of the previous readings. <br /> Sampling was performed with a 1-1/2-inch-diameter disposable polyethylene bailer <br /> suspended from new nylon line. The bailer was equipped with a bottom-release device.: <br /> Groundwater was collected with the bailer; from just below the water surface in the; <br /> monitoring well. Water samples were collected from the bailers in new 40-milliliter glass' t <br /> bottles provided by the analytical laboratory. The samples were collected so that no� s <br /> headspace was present in the bottle. The preservatives necessary for the analyses' j <br /> performed were provided in the glass bottles by the analytical laboratory. <br /> The collected water samples were placed in sealable plastic bags and packed on ice in a', <br /> portable ice chest immediately after collectio'',n. Samples were delivered within 24 hours <br /> to the analytical laboratory. Additional QA/QC procedures, including the use-of sample: <br /> identification labels and chain-of-custody forms, were followed to track sample collection, <br /> and delivery. <br /> Chain-of-Custody Records <br /> Chain-of-custody records were completed;] before the samples were packaged for; <br /> shipment. One copy of these records was placed in the project file. The second copy: <br /> accompanied the samples during transportation to the laboratory. The person in the', <br /> analytical laboratory who accepted responsibility-for these samples signed and dated the' <br /> 1� chain-of-custody record. <br /> Equipment Decontamination Procedures <br /> i� Water sampling equipment was decontamiflated between sampling events using the <br /> following procedures: <br /> I. <br /> 1 . Rinse with water using a brush. <br /> 5:\SFS\STOCKTON\LTR\LTROOB.DOC 5/1/01 <br />